The form of supporting plates for the support of rotors, in particular of open-end spinning rotors, has been the subject of many studies and designs. The high speeds required in these rotors, today reaching a maximum of 150,000 RPM in the rotor and having a tendency to ever higher rotational speeds, lead to a considerable heating up of the supporting plates, in particular of the support ring situated on it. This heat must be dissipated because it is often the cause of damage to the support ring.
The above-mentioned problem is addressed by German Patent GM 84 33 579. In order to increase the surface life of the spinning rotor at extremely high rotational speeds, provision is made in the contact surface of the support ring for a circumferential ring groove. In this manner, it is thought to achieve an improvement in the heat dissipation, so that the danger of heat accumulation inside the support ring is reduced.
German Patent PS 195 11 000 also concerns a supporting plate having improved cooling, in order thus to achieve a longer surface life of the supporting plate. For this purpose, the support ring is provided with cooling fins, which provide thermal relief.
The heat arising in the support ring, in connection with the flexing work in the polymer support ring, can lead to the separation of the support ring from the hub ring. In order to avoid this, it is necessary to anchor the support ring to the hub ring very well. German Laid-Open Print 42 27 489 deals with this problem and provides for a profiling, by which support ring and hub ring are joined to each other. However, the manufacture of the profiling in this case is extremely expensive. Furthermore, in this design, the heat dissipation is critical in the relatively thick edge areas of the support ring.
The problem of heating and the related problem of wear is also the subject of German Laid-Open Print 37 19 445. For this purpose, provision is made there for introducing a highly planar ring groove into the contact surface of the support ring, to reduce the stress in this area on the supporting plate by the shaft of the spinning rotor. The contact surface is to be relieved in its central area.
Finally, U.S. Pat. No. 4,713,932 should also be mentioned, in which, for heat dissipation, the support ring has a reduced thickness in its center, so that at least in the central area of the support ring the amount of heat generated will be less, while also maintaining a sufficient damping capacity. Here, too, the relatively thick edge areas generate problems in heat dissipation.